RequirePackage{luatex85}
documentclass[tikz]{standalone}

usepackage{pgfplots}
pgfplotsset{compat=newest}

begin{document}
    begin{tikzpicture}
    begin{axis}
    addplot3[contour filled] table {P.dat};
    end{axis}
    end{tikzpicture}
end{document}

RequirePackage{luatex85}
documentclass{standalone}

usepackage{pgfplots}
usepgfplotslibrary{patchplots}
pgfplotsset{compat=newest}

begin{document}
    begin{tikzpicture}
    begin{axis}[view={0}{90}]
    addplot3[contour filled,mesh/rows=31,mesh/cols=11,mesh/check=false] table {P2.dat};
    end{axis}
    end{tikzpicture}
end{document}